Artificial respiration devices for applying and relieving pressure on the chest of a person have been used to assist in lung breathing functions, and loosening and eliminating mucus from the lungs. Subjecting the person's chest and lungs to pressure pulses or vibrations decreases the viscosity of lung and air passage mucus, thereby enhancing fluid mobility and removal from the lungs. These devices use vests having air accommodating bladders that surround the chests of persons. Mechanical mechanisms, such as solenoid or motor-operated air valves, supply air under pressure to the bladders in regular patterns of pulses. J. D. Ackerman et al in U.S. Pat. No. 2,588,192, discloses an artificial respiration apparatus having a chest vest supplied with air under pressure with an air pump. Solenoid-operated valves control the flow of air into and out of the vest in a controlled manner to pulsate the vest, thereby subjecting the person's chest to repeated pressure pulses. W. J. Warwick and L. G. Hansen, in U.S. Pat. No. 5,056,505, disclose a chest compression apparatus having a chest vest surrounding a person's chest. A motor-driven rotary valve allows air to flow into the vest and vent air therefrom to apply pressurized pulses to the person's chest.
R. S. Dillion in U.S. Pat. No. 4,590,925 uses an inflatable enclosure to cover a portion of a person's extremity, such as an arm or leg. The enclosure is connected to a fluid control and pulse monitor operable to selectively apply and remove pressure on the person's extremity. R. L. Weber in U.S. Pat. No. 3,672,354 discloses a rest inducing device having an air mattress supplied with air in pulses from an air pump at the frequency of the person's heartbeat.